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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Lead above Window Opening https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1235259676 Message started by Gammy_leg on Feb 21^st, 2009, 11:41pm

Title: Lead above Window Opening
Post by Gammy_leg on Feb 21^st, 2009, 11:41pm

I have noticed on the outside wall of my house there is a strip of lead that stretches across one of the window openings about 2 or 3 courses above. What was this used for? It looks like where the lead finishes either side, it is replaced by bitumen instead. Is this some kind of damp proof course? ( Built 1930's, some mods during WW2 )

Thanks

Gammy

Title: Re: Lead above Window Opening
Post by CWatters on Feb 22^nd, 2009, 10:39am

Do you have cavity walls? It sounds like a cavity tray. It's designed to deflect any water running down inside the cavity to the outside. Stops it pooling on the lintel and crossing to the inside.

Title: Re: Lead above Window Opening
Post by Gammy_leg on Feb 22^nd, 2009, 1:38pm

CW,

Yes, there is a cavity. As for lintels I have exposed a timber lintel inside but have yet to find an exterior one. I have noticed a lot of houses round here have the same lead strip above window openings so it was obviously common practice to install. There are no obvious weep holes in the wall so can I assume that if it were a cavity tray that the water would run off each end into the cavity?

Strange thing is the second identical window opening in the same room doesn't have this lead strip.

Thanks

Gammy

Title: Re: Lead above Window Opening
Post by trowelhead on Feb 22^nd, 2009, 7:32pm

I always thought these lead protrusions were to stop the rain running down the wall into the window reveal and down the window?
Its definitely nothing to do with weeps for a lintel,as somebody else said, there are never any weep holes.
The only reasons i can see it missing from other openings is the window was fitted later or the strip has been removed!

Title: Re: Lead above Window Opening
Post by Gammy_leg on Feb 22^nd, 2009, 7:46pm

Trowelhead,

I can see the logic in fitting as a drip and i'm sure it would have been added when that section of the house was repaired after the WW2 bomb damage. I have still got the cavity open not far away so I will prod about to see if it extends into the inner wall

Gammy

Title: Re: Lead above Window Opening
Post by JerryD on Feb 22^nd, 2009, 10:25pm

We've recently demolished part of a house that had these lead strips. They were cavity trays deflecting water to the outer skin of the cavity. Any water that did not soak into the outer wall would have dripped off the ends of the lead and down the (empty) cavity. No weep holes were evident.